Firestop block and thermal barrier system for fluted metal decks

ABSTRACT

The invention provides methods, systems and devices for installing thermal barriers in openings or gaps in or between structures such as walls, ceilings and floors. At least one firestop block is positioned in the holes or gaps formed by the wall and a fluted metal deck of the ceiling or floor. The walls can be gypsum walls, which may have a metal track at the top or bottom, or could be block walls made of concrete or similar material. The firestop blocks are made of fire resistant material such as hydratable cement or intumescent materials. A flexible or flowable firestop material that is operative to cure or harden, such as elastomeric sealant or silicone, or hydratable cementitious slurry, is introduced into the space between the firestop block and the hole or gap, as a sealant or filler.

FIELD OF THE INVENTION

The present invention relates to firestop blocks and a thermal barrier system for building structures, and more particularly to thermal barriers for “head-of-wall” joint assemblies between tops of walls and ceilings or floors.

BACKGROUND OF THE INVENTION

Firestops are thermal barrier materials or combinations of materials used for filling gaps and openings such as in the joints between fire-rated walls and/or floors of buildings. For example, firestops can be used in walls or floors to prevent fire and smoke from passing through the gaps or openings required for cables, pipes, ducts, or other conduits. Firestops are also used to fill joint gaps that occur between walls, between a ceiling and the top of a wall (“head-of-wall” joints), and between a floor and vertical wall (“perimeter” joints).

So-called “head-of-wall” joints pose a number of challenges for the firestopping industry. Walls are generally made of concrete block or other type of fire resistant block. Ceilings (or floors) are increasingly being made by pouring concrete onto fluted steel. Walls are also increasingly being made of gypsum wallboard affixed to a framework of metal studs capped by a horizontally extending track. Although the distance between the concrete block wall or horizontally extending track at the top of the wall is often fixed in relationship to the ceiling, the concrete block and gypsum wallboards are subject to expansion and contraction due to motion of other building components, ground settling, or other causes.

For such head-of-wall joints, it is known to use mineral wool batt as a thermal resistant firestop material due to its ability to provide for cyclic movements in the wallboard material. Mineral wool batt is also used at the head-of-wall joints for block walls. See, e.g., U.S. Pat. No. 4,756,945. The mineral wool is cut into separate sheets that are appropriately sized depending on the specific geometry of the fluted steel ceiling. The sheets need to be stacked and compressed (e.g., a minimum 50%) when packed into the joint gap. In some situations, a fireproofing material is spray-applied into the spaces of the fluted ceiling to supplement the mineral wool in the joint. In either case, the mineral wool approach requires labor and time.

After packing of the mineral wool batt into place above the wall, the construction worker must then spray an elastomeric coating, using a minimum one-eighth inch thickness, against the exposed side surfaces of the compressed mineral wool layers. The coating must overlap a minimum of one half inch onto the ceiling and wall surfaces. Thus, the use of mineral wool batt and elastomeric spray coating provides for the ability of the resultant firestop to accommodate some cyclic movement (compression and extension) in various components such as the gypsum wallboards on either side of the head-of-wall joint.

In addition, a thermal barrier and method is known that employs introducing into the opening or gap at least one (empty) thermal barrier molding bag to receive a flowable firestop material that is to expand the bag within the hole or joint gap and harden within the bag; thereby molding a thermal barrier within the hole or joint gap. See U.S. Pat. No. 7,043,880. This method is inconvenient, labor intensive and time-consuming, and therefore quite costly.

One objective of the present invention is to provide a more convenient and cost-effective method for installing a thermal barrier in shaped openings and joint gaps such as are found in “head-of-wall” joints.

Another objective of the invention is to provide novel thermal barriers that may be used conveniently and safely in hard-to-reach building or ship vessel joint gaps or holes. For example, the location of a head-of-wall joint next to an elevator shaft or crawl space would render difficult the installation of mineral wool/coating systems, because the task of coating both sides would be complicated by the lack of convenient access. With the present invention, a thermal barrier for both sides could be completed while the wall is being built, thereby obviating this problem.

A still further objective of the invention is to enhance safety of installation. An applicator must climb up and down ladders on a frequent basis when working on head-of-wall joint assemblies. In the first instance, there is the fitting and hand-packing of mineral wool material into the joint gap. In the second instance, there is the coating of elastomeric material to create a continuous surface between the ceiling, firestop, and wall. In both cases, the ladder may require frequent repositioning, and this is especially the case where joint gaps extend lengthy distances of ten to twenty feet or more. Frequent climbing up and down ladders would also be required in “perimeter barrier” systems if it were desired to apply an elastomeric coating onto the bottom face of a mineral wool firestop that has been packed between a floor and a wall, because the installer would need to go to the floor below the firestop to coat the bottom face of the mineral wool material. With the present invention, it is not necessary to repeatedly access the work area.

In view of the prior art disadvantages, novel thermal barriers and methods are believed to be needed.

SUMMARY OF THE INVENTION

In surmounting the disadvantages of the prior art, the present invention provides a method and system for installing a thermal barrier in openings and gaps in or between building structures such as walls, ceilings and floors. In so doing, the present invention provides increased convenience, effectiveness and safety in comparison to the prior art mineral wool/coating and other methods. The thermal barriers of the present invention have the ability to conform to the openings and gap spaces between the tops of walls and fluted metal decks. The thermal barriers also have the ability to permit movement of the various building structures around the openings or gaps. In particular, protection on both sides of “head-of-wall” joint assemblies (arising between a wall and ceiling), may be conveniently accomplished by the thermal barriers and methods of the present invention.

An exemplary method of the present invention comprises providing a first and second structure which define therebetween a gap, such as the joint gap between a wall and a fluted ceiling, introducing into the opening or gap at least one firestop block that is constructed of firestop material and configured to be slideably inserted into the fluted opening between the wall and the floor. A flexible firestop material, such as an elastomeric sealant, silicone, polyethylene or polyurethane foam backer rod, or spray, as are commercially available, is supplied as a sealant of filler between any remaining space between the firestop block and the wall or fluted metal ceiling, thereby forming a molded a thermal barrier within the fluted hole or gap.

The firestop blocks of the invention can be made of any dense, firestop material as recognized in the UL Fire Resistance Directory, 2007 ed., which is incorporated herein by reference, but cementitious materials such as concrete blocks (CAZT) or pre-cast concrete units (CFTV) are preferred. In addition, the firestop blocks may be made of fire resistant intumescent materials, which expand when they are heated, as by a fire. Intumescent materials, however, may be more expensive than cementitous materials. Although the firestop blocks can be of any shape to match the shape of the fluted metal deck, they are generally configured as trapezoidal shaped bars and are dimensioned to be slidably inserted into the openings created at the tops of walls and the fluted metal deck setting on top of the wall. The base and height of the firestop blocks may be of any dimension as required by the shape of the flutes on the metal deck, but are generally about 4-6 inches wide, with about 5 inches being preferred, are generally 1-4 inches high, with 2½ inches being preferred. The firestop blocks may also be of any length, but generally, 16 to 18 inches is preferred.

Typically, both the floor and fluted metal ceiling of the structure are in place when the walls are constructed. The walls are thus built up to the fluted metal ceiling, leaving a space at the top, particularly with respect to the position of the flutes. The firestop blocks are then set on the tops of the walls and, in the case of cement block walls, are held in place by mortar on the underside of the firestop blocks. Where the wall is made of gypsum and is capped by a metal track, fire resistant adhesive can be used to attach the firestop block to the metal track. The spaces that remain on the top and sides of the firestop block and the fluted metal deck can be filled or sealed using intumescent fillers, caulks or sealers as are available commercially, e.g., such as hydratable cementitious slurry, an intumescent material, a superabsorbent polymer; silicone; polyurethane (foam); hydrated silica gel; inorganic dessicants (e.g., molecular sieves such as zeolites; silica gel; calcium oxide; calcium sulfate; calcium chloride; barium oxide; phosphorous pentoxide); fibers; mineral wool; fiber glass; or mixture thereof.

Firestop barriers made in accordance with the above-described in-situ methods of the present invention provide excellent fire resistance and sealing ability as well as smoke and acoustic barrier properties that also provides for flexibility. They are also sufficiently strong to resist dislodgement from the gap or opening due to pressure (e.g., force from a water hose) and are highly amenable to visual inspection.

Further features and advantages of the invention are described in detail hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of exemplary embodiments may be more readily appreciated in conjunction with appended drawings, wherein:

FIG. 1 is a perspective view of a so-called “head-of-wall” joint assembly for a gypsum wall (PRIOR ART);

FIG. 2 is a perspective view of a so-called “head-of-wall” joint assembly for a block wall (PRIOR ART);

FIG. 3 is a perspective diagram of a mineral wool batt firestop “head-of-wall” joint assembly (PRIOR ART);

FIG. 4 is a perspective view of a firestop block for a fluted metal deck;

FIG. 5 is an elevation sectioned view of a firestop block for a fluted deck in use on a concrete masonry (“CMU”) wall illustrating deck flutes perpendicular to the CMU wall; and

FIG. 6 is an elevation sectioned view of a firestop block for a fluted deck in use on a CMU wall illustrating deck flutes parallel to the CMU wall.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings wherein the showings are for purposes of illustrating different embodiments of the present invention and not for purposes of limiting the same, FIG. 4 perspectively illustrates a firestop block 10 configured to be slidably inserted into a fluted opening 42 (see FIG. 1) of a fluted metal deck 40.

The present invention employs one or more thermal barrier firestop blocks 10 that may be conveniently placed in openings in a structure, such as a wall, ceiling, or floor, or conveniently placed in gaps such as are defined in the joints between walls, ceilings, and/or floors. The firestop blocks are placed in the hole or joint gap formed between the head of a wall and a fluted metal deck. A flexible firestop material is introduced around the firestop block, thereby filling and sealing the space within the hole or joint gap and the fluted deck, and the filler/sealant firestop material is then allowed to harden within the hole or joint gap to provide a strong thermal barrier.

As shown in FIG. 1, a “head-of-wall” joint gap fluted opening 42 appears between the top of a vertical wall 44 and fluted metal ceiling or deck 40 (PRIOR ART). In this case, the wall is made by attaching a horizontal metal track 46 or runner to a fluted metal ceiling 40 which runs in a perpendicular manner to the wall 44. The fluted metal ceiling 40 has fluted portions 40B which are somewhat lower than the top ceiling portion 40A, and thus a fluted opening 42 is defined between the top ceiling portion 40B and the top of the wall, which in this case is the horizontal track 46. Metal studs 48 are attached to the horizontal track 46 and connected to the floor below. Gypsum wallboards can be affixed on either side of the studs 48 to complete the wall assembly (PRIOR ART), and gaps 49 are typically left between the tops of the horizontal track 46 to permit movement of the wallboards. Typically, the fluted joint gap openings 42 can be about 5 inches wide at its narrowest point and about 6 inches wide at its widest point, although these dimensions may vary. Also, the height of the fluted joint gap openings 42 can vary, but generally is about three inches.

Similarly, FIG. 2 illustrates a “head-of-wall” joint for a concrete block wall where gap fluted joint gap openings 42 appear between the top of the concrete block wall 45 and fluted metal ceiling or deck 40 (PRIOR ART). The fluted metal ceiling 40 has fluted portions 40B which are somewhat lower than the top ceiling portion 40A, and thus a fluted joint gap opening 42 is defined between the top ceiling portion 40B and the top of the wall. Metal studs 48 are attached to the horizontal track 46 and connected to the floor below. Gaps 49 are typically left between the tops of the concrete block wall 45 and the fluted metal deck 40. As illustrated, the fluted joint gap openings 42 can be about 6 inches wide and the height of the fluted joint gap openings 42 is about 3 inches.

FIG. 3 illustrates the prior art mineral wool batt system used to fill the fluted joint gap opening 42 and gaps 49. There, the mineral wool batt is folded into the desired thickness and inserted into the corresponding openings.

As shown if FIG. 4, an exemplary firestop block 10 of the invention. The firestop blocks of the invention are made of any dense, firestop (or fire resistant) material as recognized in the UL Fire Resistance Directory, 2007 ed., which is incorporated herein by reference. Cementitious materials such as concrete blocks (CAZT) or pre-cast concrete units (CFTV) are preferred. Hydratable cementitious materials are also preferred. In addition, the firestop blocks may be made of fire resistant intumescent materials, which expand when they are heated, as by a fire.

The firestop blocks 10 of the invention are configured to conform to fluted joint gap openings 42. Specifically, firestop block 10 is shaped as an elongated trapezoid, having a width dimension 12, a height dimension 14 and a length dimension 16. These dimensions are designed to generally conform to the corresponding dimensions of fluted joint gap openings 42, but are sufficient to allow a space between the firestop block 10 and the fluted metal deck 40. The base and height of the firestop block 10 may be of any dimension as required by the shape of the flutes 40A and 40B on the metal deck 40, but generally, the width 12 of firestop block 10 is about 4-6 inches, with about 5 inches being preferred. The height 14 of the firestop blocks 10 are generally about 1-4 inches, with 2½ inches being preferred. The firestop blocks 10 may also be of any length 16, but generally, about 16 or 18 inches is preferred. In addition, the firestop blocks 10 of the invention may contain scoring 18 on the upper surface 17 of the block 10, so that the length 16 of the blocks 10 can be easily shortened by breaking the blocks at the scoring points in, in a manner known by masons. The scorings 18 can be located in any desired position on the upper surface 17 of the blocks, but are preferred to be in the center and in “quarter” positions so that the blocks 10 can be broken into 12 inch, 8 inch and 4 inch blocks to match the width of a CMU wall.

As shown in FIG. 5, an exemplary thermal barrier 1 of the invention is made by inserting at least one firestop block 10 at the top of a CMU wall 30 between the top of the wall 32 and top ceiling portion 40A of the fluted metal ceiling 40. As seen in FIG. 5, the direction of the wall 30 is perpendicular to the direction of the fluted joint gap openings 42 of the fluted metal ceiling 40. In this embodiment, the firestop blocks 10 can be inserted lengthwise into the fluted joint gap openings 42, after the length 16 is adjusted to the width of the wall 30, if necessary. The fluted metal ceiling 40 is connected to the top 32 of wall 30 by applying a mortar material 50 to the top of the wall 30. Thus, the fluted metal ceiling 40 is on the top of mortar 50 on top of wall 30. When the firestop blocks 10 are inserted into the fluted joint gap openings 42, the firestop blocks rest on top of the mortar 50 and are held in place when the mortar 50 hardens.

A flexible sealant or filler material 20 is then introduced into the remaining gap 22 in the fluted joint gap opening 42 between the firestop block 10 and the fluted ceiling 40, which is generally about ½ of an inch. Both the mortar 50 and the sealant material 20 protect the exposed fluted joint gap opening 42, so that heat and smoke do not penetrate through the wall at the top portion.

The sealant material 20 can be made of any flexible spacer material, such as intumescent fillers, caulks or sealers as are available commercially, e.g., such as hydratable cementitious slurry, an intumescent material, a superabsorbent polymer; silicone; polyurethane (foam); hydrated silica gel; inorganic dessicants (e.g., molecular sieves such as zeolites; silica gel; calcium oxide; calcium sulfate; calcium chloride; barium oxide; phosphorous pentoxide); fibers; mineral wool; fiber glass; or mixture thereof.

As shown in FIG. 6, another exemplary thermal barrier 1 of the invention can be made when the fluted metal ceiling 40 is oriented in the same direction as, or parallel to, the CMU wall 30. In this case, the firestop blocks 10 are positioned on top of the wall 30 parallel to the direction of the wall. Enough firestop blocks 10 are inserted to fill the entire length of the fluted joint gap opening 42. Thus, no fluted joint gap opening 42 appears on top of the wall in this case (because the spaces defined between ceiling surfaces 40A and 40B do not appear on either side of the wall). However, firestop sealant material 20 is introduced along the edges, such that a thermal firestop barrier is formed at the top of the wall 30.

Thus, an exemplary method of the invention comprises inserting at least one firestop block 10 into the fluted joint gap opening 42 between two structures, such as a wall and ceiling, affixing the firestop blocks 10 on its bottom surface using a mortar material, then introducing a firestop sealant material into the spaces 22 (FIG. 5) between the top and sides of the firestop block 10 and the fluted ceiling 40, allowing the mortar and sealant material to harden inside the fluted joint gap openings 42, whereby a thermal barrier is formed.

The thermal barriers of the invention are contemplated primarily for use in joint assemblies (e.g., floor-to-floor joint systems, wall-to-wall joint systems, floor-to-wall joint systems, and head-of-wall joint systems).

The term “hydratable cementitious” material as used herein refers to material that comprises at least one cementitious binder that begins to harden when mixed with water. Such a binder may be Portland cement, masonry cement, or mortar cement, gypsum, stucco, Plaster of Paris, aluminous cement, pozzolanic cement, magnesium oxychloride, magnesium oxysulfate, calcium silicate-hemihydrate, as well as materials such as limestone, hydrated lime, fly ash, blast furnace slag, and silica fume. The hydratable cementitious materials may in addition optionally include fine aggregates (e.g., sand), coarse aggregates (e.g., crushed stone, gravel, carbon flakes), or other fillers. Further exemplary cementitious materials may optionally contain, in addition to the cementitious binder, an intumescent material as will be further described hereinafter.

Exemplary hydratable cementitious materials used as flexible firestop materials in the present invention may further include one or more admixtures or additives, such as set accelerators, set retarders, water reducers (including superplasticizers and fluidity enhancing agents), rheology modifiers, air entraining agents, pigments or colorants, porous aggregates (e.g., shredded expanded polystyrene, expanded vermiculite, perlite, etc.), fibers, rheopectic agents (e.g., granular attapulgite, sepiolite, or mixtures thereof), surfactants, and other admixtures as conventionally known in the art.

Numerous patents and publications have disclosed intumescent compositions containing one or more polymeric materials in combination with phosphate-containing materials and carbonific or carbon-yielding materials, and such compositions, as known in the art, are believed to be suitable for use as firestop materials of the present invention. See, e.g., U.S. Pat. No. 3,513,114 of Hahn et al.; U.S. Pat. No. 5,487,946 of McGinniss et al.; U.S. Pat. No. 5,591,791 of Deogon; U.S. Pat. No. 5,723,515 of Gottfried; World Patent No. WO 94/17142 (PCT/US94/00643) of Buckingham; and World Patent No. WO 98/04639 (PCT/US96/12568) of Janci, all of which are incorporated fully herein by reference.

Other exemplary intumescent materials include graphite flakes impregnated with sulfuric or nitric acids. Inorganic material flakes capable of exfoliation when heated include vermiculite and perlite.

When installed in the joint gap of a building structure, the in-situ thermal barriers of the invention are tightly conformed to the shape of the structure or structures surrounding/defining the joint gap. It is envisioned that preferred thermal barriers of the invention, when installed in joint assemblies, are capable of passing fire endurance tests and hose stream tests in accordance with the “UL Standard for Safety for Tests for Fire Resistance of Building Joint Systems, UL 2079,” Third Edition, Dated Jul. 31, 1988, (Underwriters Laboratories, Inc., Northbrook, Ill.), incorporated fully herein by reference.

The foregoing discussion and examples are provided for illustrative purposes and not intended to limit the scope of the invention as claimed. 

1. A building joint structure, comprising: a thermal barrier in a joint gap between a first structure comprising a wall and a second structure comprising a ceiling or floor, said thermal barrier comprising at least one firestop block, the firestop block comprising an acceptable fire resistant material that is configured to conform to the dimensions of the join gap.
 2. The joint structure of claim 1, wherein the structure comprising the ceiling or floor is a fluted metal deck.
 3. The joint structure of claim 1, wherein the acceptable fire resistant material of the firestop block comprises a cementitious material, a hydratable cementitious material or an intumescent material.
 4. The joint structure of claim 1, further comprising a flexible or flowable fire resistant filler material contained within spaces between the joint gap and the firestop block, thereby sealing the joint gap.
 5. The joint structure of claim 4, wherein the flexible of flowable fire resistant filler material is an intumescent material.
 6. The joint structure of claim 1, wherein said firestop block is located in a head-of-wall joint.
 7. A firestop block made of acceptable fire resistant material having a top surface, a bottom surface, side surfaces and end surfaces, and wherein said firestop block is configured to conform to the dimensions of a joint gap between a first structure comprising a wall and a second structure comprising a ceiling or floor.
 8. The firestop block of claim 7, wherein the ceiling or floor is a fluted metal deck.
 9. The firestop block of claim 7, wherein the fire resistant material comprises a cementitious material, a hydratable cementitious material or an intumescent material.
 10. The firestop block of claim 9, wherein the firestop block is configured in the shape of an elongated trapezoid.
 11. The firestop block of claim 10, further comprising at least one scoring mark on the top surface for breaking the firestop block at the location of the scoring marks.
 12. A method of creating a thermal barrier in a building joint gap between a first structure comprising a wall and a second structure comprising a ceiling or floor, comprising the step of: inserting into said joint gap at least one firestop block comprising an acceptable fire resistant material that is configured to conform to the dimensions of the join gap.
 13. The method of claim 12, further comprising the step of filling or sealing the space between the joint gap and the firestop block with a flexible fire resistant material.
 14. The method of claim 13, wherein the structure comprising the ceiling or floor is a fluted metal deck.
 15. The method of claim 12, wherein the firestop block comprises a cementitious material, a hydratable cementitious material or an intumescent material.
 16. The method of claim 13, wherein the flexible fire resistant material is an intumescent material.
 17. The method of claim 12, wherein the firestop block is configured in the shape of an elongated trapezoid. 